Self-locking electrical connector



Feb. 28, 1950 THERIAULT SELF-LCCKINC ELECTRICAL CONNECTOR 2 Sheets-Sheet1 Filed Dec. 28, 1946 Feb. 28, 1950 f THERIAULT 2,498,743

SELF-LOCKING ELECTRICAL CONNECTOR Filed Dec. 28, 194e z sneets-sheetz'Patented Feb. 28, 19

'UNITED STATES PATENT OFFICE 2,498,743 SELF-LOCKING ELECTRICAL CONNECTORLucien Theriault, New Haven, Conn.

Application December 28, 1946, Serial No. 719,049

(Cl. 3P-361) Claims. l

The present invention relates to improvements in electrical connectorsand relates more particularly to improvements in self-locking electricalconnectors which are designed and adapted for rapid connection to anddisconnection from another electrical fitting.

Such an electrical connector, having related subject matter, is shownand described in my copending application, Serial No. 12,227.

While the self-locking electrical connectors of the present inventionare available for many other uses, one of the main uses is in the formof a plug-member having one or more projecting blades or prongs whichmay form the terminal of one or more conductors leading to portableelectrical devices such, for instance, as radios, toasters, heaters,etc.

One oi the main objects of the present invention is to provide asuperior electrical connector which may be produced at a low cost formanufacture and which embodies simple, convenient, effective means forreleasably locking the connector to another electrical fitting such, forinstance, as a wall outlet.

Another object of the present invention is to provide a superiorself-locking electrical connector which may have its locking-meansrendered effective and ineffective ,in a manner natural to and easilyunderstood by unskilled users.

Another object of the present invention is to provide a superiorelectrical connector of the character referred to, which is simple toassemble and simple to disassemble for purposes of connecting one ormore electrical conductors there- In the accompanying drawings, in whichcertain modes of carrying out thek present invention are shown forillustrative purposes:

Fig. 1 is a view mainly in side elevation of one form of self-lockingelectrical connector embodying the principles of the present invention,but with the operating-sleeve partly in section and 2 with thelocking-arms in their retired or nonlocking position;

Fig. 2 is an edge view thereof;

Fig. 3 is a view looking toward the inner or blade-end of the connector;

y Fig. 4 is a transverse sectional view taken on the line 4-4 of Fig. 1;A

Fig. 5 is a central-longitudinal sectional view taken on the line 5-5 ofFig. 1;

Fig. 6 is a view similar to Fig. 1 but with a portion of the body-memberand one of the bladeunits in section and showing the locking-arms intheir advanced or locking positions;

Fig. 7 is a sectional view taken through the major plane of theelectrical connector and showing the same as engaged with and locked toan electrical outlet;

Fig. 8 is a similar view but showing the operating-slide moved outwardlyto retract the lockingarms;

Fig. 9 is a perspective-view partly in section of the body-memberdetached;

Fig. 10 is a similar view of the operating-slide;

Fig. 11 is a perspective view of one of the bladeunits detached andlooking mainly toward the outer face thereof; and

Fig. 12 is a similar view but looking mainly toward the inner face ofthe blade-unit.

The particular self-locking electrical connector,

herein chosen for purposes oi illustrating a preferred form of thepresent invention, is in the form of a double-bladed plug-member of atype designed for connecting door lamps, radios, toasters, etc., to asource of current supply.

The device illustrated includes a body-member generally designated bythe reference character l0, reciprocating operating-*sleeve generallydesignated by the reference character Il and a pair of contact-bladesrespectively generally designated by the reference characters |2|2. Thesaid body-member I0 and operating-sleeve Il may be molded from anysuitable insulating material such as hard rubber, soft rubber or anysuitable thermoplastic or thermosetting resin.

The body-member lil is suitably cored to provide in its interior,adjacent its inner end, a cavity I3 which is connected to the adjacentinner end of the said body-member by a passage I4. The said body-memberis generally of rectangular form in cross section and is formed in itsre spective opposite side edges with longitudinal op# positely-facingblade-receiving grooves I5-I5 respectively serving to receive thecontact-blades l2-I2 and to hold the same in laterally-spacedapartrelationship.

Ihe body-rneisiber is so formed the outer portion of the cavity i3 isdivided foy a transverse web and laterally intersects the respectiveupper ends of the blade-receiving grooves Iii-itl, as is especially weilshown in Figs. 7, 3 and 9. By reference to the drawings, it will be seenthat the bottom of the cavity I Si provides on each of the respectiveopposite sides of the web i6, upwardly-facing ledges III--I`I,forpurposes as will hereinafter appear. Beneath each of the ledges II-'I'Lthe body-member is formed with one of two clearance-recesses I8IBrespectively communicating with the adjacent one of the bladereceivinggrooves I--I5.

Each of the contact-blades I2-I2 are of corscription of one thereof willserve for both.

In the instance shown, each contact-blade I2-I 2 is folded up from springy sheet metal and comprises a plate-like inner portion I9 which 'isformed along each of its respective opposite side Vedges with one of twoparallel side-flanges -20 which extend substantially throughout thelength of the portion I9. Adjacent its upper end, the

plate-like inner portion I9 is pierced and struck outwardly to provide apair of complemental screw-retaining fingers 2I-2I, for purposes as willhereinafter appear.

Formed integral with the upper edge of the plate-like inner portion I9of each contact-blade I2, is ra downwardly-extending locking-arm 22which is sufficiently narrow to freely fit between the respectiveside-flanges 2li-20, asis especially well shown in Fig. 11. In line withthe substantiallv-circular gap between the endsof the screwretainingfingers 2I2I, the said locking-arm is formed with a clearance-opening 23for thepas sage therethrough of a binding-screw, in the manner as willhereinafter appear.

Slightly below its clearance-opening 29, the locking-arm 22 is formedwith an outwardly-anddownwardlysloping portion 24 which, in turn, isintegrally united with a substantially-fiat dwell 25. Integral with thedwell 25 and sloping downwardly and inwardly therefrom, is a cam-portion26 which, in turn. is integral with a downwardlyextending andsubstantially-flat portion 21. The extreme lower end of the portion 21just referred to is bent outwardly (and preferably slightly upwardly) toprovide a locking-finger 28, for purposes as will hereinafter appear.

is reversely bent and outwardly bowed, as at 29, to fit between thecomplemental side-flanges 2li-20, as is especially well shown in Fig.11.

Inserted through the clearance-opening 23 of a given contact-blade I2and into threaded engagement with the adiacent spring-likescrew-retaining fingers 2 I -2 I, is a binding-screw 30, as will be seenby reference to Figs. 6, 'l and 8.

Firrnly clamped between the head of a given binding-screw 30 and theouter face of the upper portion of the complemental locking-arm 22, isthe naked end of one of two similar conductors 3I-3I extending into thecavity I3 of the bodymember ID through the passage I4.

The respective locking-arms 22-22 of the contact-blades I 2-I2 aremovable between the positions respectively shown in Figs. 7 and 8 underthe control of the operating-sleeve II before referred to. The saidoperating-sleeve laterally encircles the lower portion of thebody-member I0 and reciprocates thereon.

responding construction so that a detailed de- The extreme lower end ofthe plate-like inner portion I9 of each of the contact-blades I2I2essayes iiitlfiin its entrera-.e lower end, the operatingsleeve it isformed with two tapered operatinglugs extending in opposition to eachother from the respective opposite end-walls of the saidoperating-sleeve. Each of the operatinglugs 3?--32 is adapted to engagewith the camportion 26 and the dwell 25 of the adjacent one 0f thecontact-blades I2--I2- In the lower ledges of its respective oppositeside-walls, the operating-sleeve II is formed with one of twodownwardly-opening notches 33-33 each having a downwardly-facing wallproviding a retaining-abutment 34. Each of the retainingabutments 34-34is adapted on occasion to engage with the upper surface of the adjacentone 0f two similar rib-like retaining-fingers 35-35 respectively formedat the lower ends of two similar longitudinal retaining-arms 36-36.

Each of the retaining-fingers 3'5--35 above referred to has its lowerouter corner sloped inwardly to provide it with a cam-surface 31 and theretaining-arm 36 of which it forms a part is flexible to permit theinward reti-rement of the retaining-finger, for purposes as willhereinafter appear.

Each of the retaining-arms 36--36 is adapted to flex in the adjacent oneof two longitudinal channels 38-38 formed in the respective oppositeside faces of the body-member I0. At their respective upper ends, theretaining-arms 36-36 are integral with the body-member I0 and theirrespective retaining-fingers 35-35 are adapted, under certainconditions, to be freely accommodated in the notches 33-33 in the loweredges of the opposite side-walls of the operating-sleeve I I. When theoperating-sleeve I I is moved downwardly to cause its notches 3'3-33 tofit over the respective retaining-fingers 35-35, the respective uppersurfaces of the latter will engage with the retaining-abutments 34--34and thus normally limit the downward movement of the saidoperating-sleeve.

The upward movement of the operating-sleeve I I is limited by theengagement of its upper edge with a downwardly-facing stop-shoulder 39formed upon the exterior of the body-member I0 and extending around allfour faces thereof.

The projecting lower ends of the contact-blades I2--I2 are designed andadaptedfor engagement with contact-members of another electricalconnector and for purposes of illustration there is shown in Figs. '7and 8 of the accompanying drawings, one such suitable typeof electricalconnector. The electrical connector last referred to is generallydesignated by the reference character 40 and includes a body-member 4Iformed of insulating material and provided in its upper end with a pairof funnel-shaped passages 42-42 spaced from each other a distance whichis substantially standard in the art and which corresponds to thespacing of the contact-blades The lower ends of the funnel-shapedpassages 42l2 above` referred to respectively lead into chambers 43-43formed in the body-member 4I and respectively accommodatingcontact-mennbers M which may have any suitable conductors (not shown)connected thereto and leading. for instance. from a source of electricalenergy. The otherwise open lower ends of the chambers 43-43 are closedby a removable insulating plate I5, as is shown in Figs. '7 and 8.

The chambers 43-43 in the body-member AI are larger than the inner orlower ends of the particular funnel-shaped passage' I2 communiaans neating therewith, with a result that there is formed in the saidbody-member 4| a pair of downwardly-facing locking-abutments with whichthe locking-fingers 28-28 are respectively adapted to engage, undercircumstances as will be hereinafter described.

In assembling the self-locking electrical connector illustrated in thedrawings as a preferred embodiment of the present invention, theconductors 3 |-3I may be introduced into the cavity I3 in thebody-member l0 through the passage Il at the upper end of the saidbody-member and before the operating-sleeve is installed on thebody-member. The naked end of a given conductor 3| may now be clamped byone of the binding-screws 30 to the outer face of the upper portion ofthe adjacent locking-arm 22.

After a given conductor has been connected to a given contact-blade (orprior thereto if desired), the particular contact-blade may be installedin its appropriate blade-receiving groove Il in the body-member I sothat the inner end of the given binding-screw 30 rests upon the adjacentupwardly-facing ledge I1. Under these conditions, the givencontact-blade |2 will be held against downward displacement by theengagement of its binding-screw 30 with the adjacent ledge l1 and willbe prevented from undue upward movement by its conductor 3| whichoverlies the top of the blade and is engaged by the overhanging portionof the body-member I0, as is shown in Figs. 6, 'l and 8.

After each contact-blade |2 has had its conductor 3| connected theretoand has been mounted in its particular blade-receiving groove |5 in thebody-member I0, the operating-sleeve may be slipped up over theprojecting lower ends of the said contact-blades |2-|2 and the lower endof the body-member i0. During this installing movement of theoperating-sleeve the inner corners of its respective opposite sidewallswill engage with the respective cam-surfaces 31 of the retaining-fingers35--35 and will inwardly iiex the retaining-arms 36-3BL After theoperating-sleeve has been raised suiliciently, the notches 33-33 thereinwill respectively register with the stop-fingers 35-35, therebypermitting the said stop-fingers to move outwardly into stoppingpositions under the urge ofthe flexible retaining-arms 36-36.

When the operating-sleeve is moved into its uppermost position in whichits upper edge engages with the stop-shoulder 39 on the bodymember I0,the operating-lugs 32-32 will respectively ride up the inclinedcam-portion 28 and onto the dwell 25 of the adjacent one of thelocking-arms 22 to thereby inwardly ilex and' hold the said locking-arminto the space between the side-flanges 20-20 of the complementalcontact-blade.` Under these conditions, the locking-fingers 28-28 of therespective locking-arms 22--22 will be retired into their inoperativepositions, as is shown in Figs. 1, 3 and 8.

When the operating-sleeve is moved downwardly to the limit of itsmovement in that direction, its operating-lugs 32-32 will ride clear ofthe dwells 25 and the cam-portions 26 of the adjacent contact-blades andwill thereby permit each of the said locking-arms to spring outwardlyinto the positions in which they are shown in Figs. 6 and '7.

When it is desired to couple the improved selflocking electricalconnector of the present invention to another electrical connector suchas 4l, the operating-sleeve may be at either of its two extremepositions and the projecting ends of the contact-blades |2|2 may beinserted into the passages 42-42 in the mating electrical connector 40so that the said contactblades respectively engage with thecontactmembers 44-44.

Usually a person in engaging the improved electrical connector withanother electrical connector will grasp the operating-sleeve so that thevery act of making the connection will serve to force the saidoperating-sleeve downwardly and release the two locking-arms 22-22 fromoutward fiexure.

When the improved self-locking electrical connector is engaged with themating electrical connector 4l, the respective locking-lingers 23--28will be located outwardly in position to engage with the adjacent one ofthe locking-abutments 4B in the connector 40 to thereby prevent theunintentional separation of the two electrical connectors.

When it is desired to separate the self-locking electrical connector ofthe present invention from another electrical connector such as 40, theuser may grasp the operating-sleeve and pull outwardly and this very actwill cause the said operating-sleeve to move upwardly relative to thebody-member I0. The described upward movement of the operating-sleevewill cause the operating-lugs 32-32 thereof to ride up the respectivecam-portions 26-26 of the lockingarms 22-22 to thereby flex each of thesaid locking-arms inwardly into their retired positions, as shown inFigs. 1, 3 and 8.

The inward flexure of the locking-arms 22-22 as above described will, ofcourse, retire their respective locking-lingers 28-28 and permit theseparation of the electrical connectors, in the manner illustrated inFig. 8.

When it is desired to remove the operatingsleeve from the body-member|0, the retaining-lingers 35-35 may be jointly forced inwardly` againstthe tension of their respective retaining-arms 36-36 following which thesaid operating-sleeve may be slipped oil' of the lower end of thebody-member I0.

The invention may be carried out in other speciic ways than those hereinset forth without departing from the spirit and essentialcharacteristics of the invention, and the present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

I claim:

1. A self-locking electrical connector, including in combination: abody-member provided with a. yielding retaining-arm united to the saidbody-member adjacent one of its ends and having a. stop-finger adjacentits opposite end; a contact-member carried by the said body-member; anadvanceable-and-retirable locking-member also carried by the saidbody-member and constructed and arranged to engage with anotherelectrical-member to releasably couple the connector thereto areciprocating operatingsleeve laterally encircling the exterior of thesaid body-member and slidable thereon into and out of engagement withthe stop-finger of the said yielding retaining-arm, the saidoperatingsleeve being operatively associated with the saidlocking-member to move the same in one direction between its retired andadvanced positions;

and means controlled by the said operatingf7 sleeve for moving theinciting-member the opposite direction.

2, A seif-ioelring electrical connector, including in combination: abody-men1ber; a sheetmetal combined contact-and-locking blade carried bythe said body-member and having its respective opposite edges bent toprovide spacedapart side anges, the said blade including a portionprojecting from one end of the said body-member and a. portion extendingwithin the same, a. resilient locking-arm formed integral with andprojecting outwardly from the portion of the blade within the saidbody-member and iitting between the said side-flanges, the saidlocking-arm being provided in turn with an integral locking-fingeradapted to engage with another electrical-member to releasably couplethe connector thereto; and means carried by the said body-member forflexing the said resilient locking-arm to retire its said integrallockingfinger.

3. A self-locking electrical connector, including in combination: aninner body-member; a linear contact-member carried by and projectingfrom the said body-member; an advanceableand-retirable locking-memberalso carried by and projecting from the said body-member to one side ofthe said contact-member and' having a locking-iinger adjacent its outerend constructed and arranged to engage with another electrical-member toreleasably couple the connector thereto; an operating-sleeve mountedupon and substantially completely laterally encircling the exterior ofthe said body-member and slidable with respect thereto in a directionsubstantially lengthwise of the said contactmember and also with respectto the said locking-member, the said operating-sleeve having interiorcam-means independent of and movable with respect to the saidcontact-member and locking-member, and constructed and arranged to movethe latter laterally with respect to the said contact-member in onedirection between im retired and advanced positions; and meanscontrolled by the said cam-means of the operating-sleeve for moving thesaid locking-member laterally in the opposite direction with respect tothe said contact-member.

4. A self-locking electrical connector, including in combination: aninner body-member; a linear contact-member carried by and projectingfrom the said body-member; and-retirable locking-dinger located adjacentthe projecting portion of the said contact-member laterally and movablelaterally with respect thereto and constructed and arranged to engagewith another electrical-member to releasably couple the connectorthereto; a spring-member carried by the said contact-member andprojecting from the said body-member to one side o3? the saidcontact-member, the said springmeinber in turn carrying the saidlockingnger and pre-set to yieldingly urge the latter laterally dwayfrom the said contact-member; and a reciprocating operating-sleevemounted upon and.

substantially completely laterally encircling the exterior ci? the saidbody-member and slidable.

with respect thereto in a direction substantially lengthwise of and alsowith respect to the said contact-member and spring-member, the saidoperating-sleeve having interior cam-means independent of and movablewith respect to the said contact-member and spring-member andconstructed and arranged to move the latter in the direction to move itssaid locking-linger laterally toward the said contact-member.

5. A self-locking electrical connector, including in combination: abody-member; a. sheetmetal combined contact-and-locking blade carried bythe said body-member and having its respective opposite edges bent toprovide spacedapart side-flanges, the said blade including a portionprojecting from one end of the said body-member and a portion extending'within the same, a resilient locking-arm attached to the portion of theblade within the said bodymember and projecting from the said bodymemberand movable between the said sideflanges, the saidl locking-arm beingprovided adjacent its projecting outer end with a lockingiingerconstructed and arranged to engage with another electrical-member toreleasably couple the connector thereto; and means carried by the saidbody-member for flexing the said resilient locking-arm to retire itssaid integral locking-finger between the said side-flanges.

LUCIEN THERIAULT.

REFERENCES CITED 40 The following references are of record in the iileof this patent:

UNITED STATES PATENTS Great Britain 1909

